Synthesis of 3-aminochromenes: the Zincke reaction revisited

3-Aminocoumarines and 2-iminochromen-3-amines were efficiently prepared from the Zincke-ring-opening reaction of the corresponding 2H-chromen-3-pyridinium chlorides using N-methylpiperazine. This methodology unravels the marked potential of pyridinium salts as protective groups for primary amines.These scaffolds can be considered important building blocks for new novobiocin analogues and heterocyclic compounds.